Telegram structure

sercos has a robust, clearly-defined data structure which enhances operational reliability and simplifies application development. The status of the entire network is always transparent and unambiguous. This creates the ideal conditions for simple system diagnostics at every node using standard or specialized Ethernet diagnostic tools.

sercos telegrams contain a sercos header and a data field which are embedded in the Ethernet frame. The sercos header describes the current network phase and the position of the MDT (Master Data Telegram) and AT (Answer Telegram) in the clock cycle. The MDT and AT data fields are subdivided  into three sub-fields:

Hot-plug field:

Information on slaves which are plugged in during an ongoing operation and which will have to be plugged in again

Service channel field:

Device channels for slave configuration

Real-time data field:

Device channels for slaves used to specify or query cyclical real-time data

sercos III telegrams - clearly-defined data structure enhances operational reliability and simplifies development